Carburetors for high performance internal combustion engines are usually of high flow capacity. The carburetors as well as other components of such engines often need to be modified, however, when adjustment of vehicle performance is desired. For example, if the power capacity of the engine is altered or the carburetor is used with a different engine, the carburetor capacity must be modified to ensure maximum engine performance. Similarly, when the type of fuel used is changed, the carburetor must be modified to satisfy the particular requirements associated with the new fuel type.
Most modern carburetors are produced by one-piece casting. Accordingly, costly machining or total replacement is necessary where the user desires to increase carburetor capacity. In situations in which a decrease in capacity is needed, the user has no choice but to opt for total replacement of the carburetor. Therefore, it can be appreciated that it would be desirable to be able to adjust carburetor performance characteristics quickly and inexpensively.
In addition to altering the quantity of air supplied to the engine during the combustion cycle, the carburetor user may also wish to alter the type of fuel that is used for combustion. In such circumstances, alternatively sized fuel metering circuits are required. For instance, when switching from gasoline to alcohol fuel, approximately twice as much fuel by volume must be provided to the engine to attain comparable performance. Accordingly, it can be further appreciated that it would be desirable to be able to modify these fuel metering circuits to alter the amount of fuel that is supplied to the carburetor.
Where modifications, such as those described above, are effected, it would also be desirable to provide some means for identifying the physical parameters of the carburetor, such as throttle bore dimensions and applicable fuel type, to provide the carburetor user and/or servicer with a convenient and instantaneous indication of these parameters.